Convection heater



FIG. 1 is an isometric view of the convection heater showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof; and,

FIG. 6 is a top plan view thereof. 

The ornamental design for a convection heater, as shown. 